[S390] cio: Remove grace period for vary off chpid.

The grace period handling introduced needless complexity. It didn't
help the dasd driver (which can handle terminated I/O just well),
and it doesn't help for long running channel programs (which won't
complete during the grace period anyway). Terminating I/O using a
path that just disappeared immediately is much more consistent with
what the user expects.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 6 insertions, 11 deletions

diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 07c7f19339d2..eabe018d348f 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -707,8 +707,7 @@ chp_process_crw(int chpid, int on)
         return chp_add(chpid);
 }
 
-static inline int
-__check_for_io_and_kill(struct subchannel *sch, int index)
+static inline int check_for_io_on_path(struct subchannel *sch, int index)
 {
         int cc;
 
@@ -718,10 +717,8 @@ __check_for_io_and_kill(struct subchannel *sch, int index)
         cc = stsch(sch->schid, &sch->schib);
         if (cc)
                 return 0;
-        if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
-                device_set_waiting(sch);
+        if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index))
                 return 1;
-        }
         return 0;
 }
 
@@ -750,12 +747,10 @@ __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
                 } else {
                         sch->opm &= ~(0x80 >> chp);
                         sch->lpm &= ~(0x80 >> chp);
-                        /*
-                         * Give running I/O a grace period in which it
-                         * can successfully terminate, even using the
-                         * just varied off path. Then kill it.
-                         */
-                        if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
+                        if (check_for_io_on_path(sch, chp))
+                                /* Path verification is done after killing. */
+                                device_kill_io(sch);
+                        else if (!sch->lpm) {
                                 if (css_enqueue_subchannel_slow(sch->schid)) {
                                         css_clear_subchannel_slow_list();
                                         need_rescan = 1;